systems and Parallel PWM/PPM systems.
Added setting for failsafe_max_usec. Renamed failsafe_detect_threshold
to failsafe_min_usec.
Failsafe now detects when a PPM/PWM RX isn't sending ANY data out on
CH1-4. See documentation notes regarding Graupner receivers in
Failsafe.md.
Documented failsafe system.